Idenix Pharmaceuticals and J&J unit Janssen Pharmaceuticals have formed a non-exclusive collaboration for the clinical development of all-oral direct-acting antiviral (DAA) HCV combination therapies. The collaboration will evaluate combinations including IDX719, Idenix's once-daily pan-genotypic NS5A inhibitor, simeprevir (TMC435), a once-daily protease inhibitor jointly developed by Janssen and Medivir AB, and TMC647055, a once-daily non-nucleoside polymerase inhibitor, boosted with low-dose ritonavir, being developed by Janssen.

Clinical development plans include an initial drug-drug interaction study to begin in 1Q13, followed by Phase II studies as agreed between the companies, and pending approval from regulatory authorities. The Phase II program is expected to evaluate the two-DAA combination of IDX719 and simeprevir plus ribavirin for 12 weeks in treatment-naive HCV-infected patients. Subsequently, the companies plan to evaluate a three-DAA combination of IDX719, simeprevir and TMC647055/r, with and without ribavirin. The clinical trials will be conducted by Idenix. Both companies retain all rights to their respective compounds under this agreement.

"We are very pleased to be working with Janssen and look forward to initiating a Phase II study in the first quarter of this year," said Ron Renaud, Idenix's president and chief executive officer. "This will allow us to achieve a key goal of ours for 2013, which is to advance the development of IDX719 as part of all-oral HCV combinations in two- and three-drug regimens."